Who is Dr. Omayra Torres from City of the Beasts and what is their importance?

Dr. Omayra Torres presents herself as an honorable woman, who wants to do what she can to keep the natives safe from disease. She travels with the International Geographic crew with the apparent goal of vaccinating natives against measles. In truth, she's in league with Carias and is planning to inject the natives with a deadly form of the virus that will guarantee that they all die within a few weeks.